The present invention relates to tires of motor vehicle and more particularly to a pressure indicating device for tire of motor vehicle with improved characteristics.
A conventional valve 20 of a tube-less tire is projected from rim 10 as illustrated in FIGS. 1 and 2. Valve 20 comprises a hollow cylindrical member 30 through rim 10; a tube member 40 having a lower portion secured within bore of hollow cylindrical member 30 and an upper portion with outer threaded section 402 and an inner threaded section 401; a channel member 50 having a narrow inner hole; a spring 80; a cap 60 having an outer threaded section 601; and an elongate slender bar 70 having a thin disk 701 on lower part with spring 80 anchored between the narrow inner hole of channel member 50 and a top of the elongate slender bar 70. The elongate slender bar 70 is inserted through the channel member 50 and cap 60 until disk 701 is stopped by bottom end of the channel member 50 which is in turn secured in tube member 40. Also, threaded section 601 of cap 60 is secured to the inner threaded section 401 of tube member 40. In inflating tire, air is pumped into tire through bores of cap 60 and channel member 50 by pushing down the elongate slender bar 70 by needle (not shown) for disengaging disk 701 from bottom end of the channel member 50. In the mean time, a person can know the fullness of the tire by observing the pivoting of pointer of a pressure gauge coupled to an air pump. But in a use state of tire, above air passage is closed. Further, person can only knock on the tire by hand or foot for generally determining a fullness thereof by feeling its hardness or hearing its sound prior to driving. However, such technique is not reliable. Thus improvement exists.
It is therefore an object of the present invention to provide an apparatus mounted on a valve on a tire for indicating a pressure thereof. The apparatus comprises a pressure indicator formed of transparent plastic and including a base having a scale, the base consisting of an inner hollow cylinder sleeved on the valve and an outer hollow cylinder with tops of the cylinders open, a spring put on the inner hollow cylinder having a lower end rested on a bottom of the base, a hollow disk-shaped seal put on the inner hollow cylinder being urged by a top of the biased spring, an outer ring sleeved between the seal and an inner wall of the outer hollow cylinder, an inner ring sleeved between the seal and an outer wall of the inner hollow cylinder so as to eliminate a potential air flow through an inner or outer periphery of the seal, and a cap having a downward peg engaged with the valve, the cap being releasably secured to a top of the base wherein in indicating the pressure of the tire, air is flowed from within the tire to push down the seal through the valve and the pressure indicator so that a top of the seal is aligned with one of marks of the scale, and the pressure indicator is disengaged from the valve prior to inflating the tire.
It is another object of the present invention to provide an apparatus mounted on a first valve on a tire for indicating a pressure thereof. The apparatus comprises a pressure indicator formed of transparent plastic and including a base having a scale, the base consisting of an inner hollow cylinder sleeved on the first valve and an outer hollow cylinder with tops of the cylinders open, a spring put on the inner hollow cylinder having a lower end rested on a bottom of the base, a hollow disk-shaped seal put on the inner hollow cylinder being urged by a top of the biased spring, an outer ring sleeved between the seal and an inner wall of the outer hollow cylinder, an inner ring sleeved between the seal and an outer wall of the inner hollow cylinder so as to eliminate a potential air flow through an inner or outer periphery of the seal, and a cap releasably secured to a top of the base; and a second valve formed on a top of the cap and in communication with the cap, the second valve having an elongate slender bar engaged with the first valve; wherein in indicating the pressure of the tire, air is flowed from within the tire to push down the seal through the first valve and the pressure indicator so that a top of the seal is aligned with one of marks of the scale, and in inflating the tire, air is flowed to the tire through the second valve, the pressure indicator, and the first valve.
It is a further object of the present invention to provide an apparatus mounted on a first valve on a tire for indicating a pressure thereof. The apparatus comprises a pressure indicator formed of transparent plastic and including a base having a scale, the base consisting of an inner hollow cylinder sleeved on the first valve and an outer hollow cylinder with tops of the cylinders open, a spring put on the inner hollow cylinder having a lower end rested on a bottom of the base, a hollow disk-shaped seal put on the inner hollow cylinder being urged by a top of the biased spring, an outer ring sleeved between the seal and an inner wall of the outer hollow cylinder, an inner ring sleeved between the seal and an outer wall of the inner hollow cylinder so as to eliminate a potential air flow through an inner or outer periphery of the seal, and a cap integrally formed on a top of the base; and a second valve formed on a top of the cap and in communication with the cap, the second valve having an elongate slender bar engaged with the first valve; wherein in indicating the pressure of the tire, air is flowed from within the tire to push down the seal through the first valve and the pressure indicator so that a top of the seal is aligned with one of marks of the scale, and in inflating the tire, air is flowed to the tire through the second valve, the pressure indicator, and the first valve.
The above and other objects, features and advantages of the present invention will become apparent from the following detailed description taken with the accompanying drawings.